UTST (University of Tokyo Spherical Tokamak) was built
jointly by the Takase-Ejiri Group (Department of Complexity
Science and Engineering, Graduate School of Frontier Sciences
and Department of Physics, Graduate School of Science)
and the Ono Group (Department of Advanced Energy,
Graduate School of Frontier Sciences, and Department of
Electrical Engineering, Graduate School of Engineering),
and is sited in the Transdisciplinary Sciences
Experimental Building on the Kashiwa Campus.

It is funded by Grant-in-Aid for Scientific Research (S)
to explore the formation of ultra-high beta ST plasma
using plasma merging and the sustainment of high beta
state by innovative methods using high frequency waves.
When two plasmas merge together to form a single plasma,
magnetic field lines reconnect, and the magnetic field
energy is converted to the plasma kinetic energy.
This can be utilized to reach the ultra-high beta
regime quickly. Such research has been carried out
on the TS-3 and TS-4 merging plasma devices.
However, once reconnection is finished,
the heating power goes away and the plasma decays
to a lower beta state. Therefore, it is necessary to
develop a method to sustain the plasma efficiently
in a high beta state. Since high beta plasmas have
extremely high dielectric constants, most waves are
not accessible to the plasma core. New methods using
exotic waves such as the high harmonic fast wave (HHFW)
and the electron Bernstein wave (EBW) have been developed
on the TST-2 spherical tokamak device.
Expertise in these different areas are combined to
challenge the difficult task of creating and maintaining
a high beta ST plasma using unique methods.